Breast cancer not linked to abortion

A study of 105,000 women finds no link between abortion or miscarriage and …

Like human embryonic stem cell research and the right to die, abortion is an anathema to bioconservatives. From the 1950s until the 1990s, there were occasional reports in epidemiological studies that there was an increased risk of breast cancer following induced abortions, and this was seized upon by anti-abortion campaigners in their battle to outlaw such procedures in the US.

A few years ago, the National Cancer Institute, the branch of the NIH that deals with cancer, held a workshop of cancer experts who came to the conclusion that such a link did not exist, but that never really satisfied opponents of abortion. Now a new study, published in the Archives of Internal Medicine* has used data from the Nurses’ Health Study II (NHSII), a large scale study of 105,716 subjects, to examine whether abortion or miscarriage are indeed risk factors for breast cancer.

21 percent of the respondents had a history of miscarriage, and 15 percent a history of induced abortion, yet there was no association between these groups and the prevalence of breast cancer. There was an association between induced abortion and a specific type of breast cancer (progesterone receptor-negative breast cancer), and an inverse link between miscarriage before the age of 20 and breast cancer, although the authors caution that in both cases the number of women in each subgroup is much smaller than the main population.

Although this research neither makes a case for or against elective abortions, it does add further weight to the NCI's claim that there is no link between abortion and breast cancer.